Assembly of a one-way clutch and a bearing

ABSTRACT

An assembly of a one-way clutch and a bearing in which a thrust load due to a stator is absorbed and a dynamic pressure is generated is configured to prevent an abrupt temperature rise even when the pressure becomes high so that wear of sliding faces is prevented. The assembly of the one-way clutch and bearing is attached a stator of a torque converter. Dynamic pressure grooves and an escape groove serving as the bearings are formed in at least one of opposing faces of a flange portion formed on the stator and a pump member, or opposing faces of a bearing support which is placed on the side opposite to the flange portion of the stator, and a turbine member.

TECHNICAL FIELD

The present invention relates to an assembly of a one-way clutch and abearing which is to be attached to a stator of a torque converter, andmore particularly to an assembly of a one-way clutch and a bearing inwhich a thrust bearing (needle bearing), a thrust washer, and the likeare not used, and wear of sliding faces of a stator and a bearingsupport can be reduced.

BACKGROUND ART

A torque converter which is used as an automatic transmission of anautomobile is configured so that, as shown in FIG. 9, a pump impeller 2is rotated by an output shaft 1 of an engine, a turbine runner 4 isrotated by using ATF (Automatic Transmission Fluid), the rotationaltorque of the turbine runner 4 is increased via a stator 3, and thepower is then transmitted to an input shaft 5 of the transmission. Aone-way clutch 6 is attached to the stator 3. An inner race 6 b of theone-way clutch 6 is non-rotatably placed by spline fitting or the likeon a stationary shaft 11 which is placed around the input shaft 5.Depending on the vane angle of the stator a thrust load is applied tothe one-way clutch 6. In order to absorb the load, therefore, thrustbearings 12 and 13 (or thrust washers) are usually placed on both thesides of the one-way clutch 6, respectively.

When the thrust bearings 12 and 13 (or thrust washers) are placed onboth the sides of the one-way clutch 6, however, the number of parts isincreased, the configuration is complicated, and it is disadvantageousfrom the view point of space. Consequently, the assignee of the presentapplication has proposed an assembly of a one-way clutch and a bearingin which, as shown in FIG. 6, such a thrust bearing 12 and the like arenot used, small gaps 21 and 20 are respectively formed between a flangeportion 3 b, that elongates radially inward from a boss portion 3 a ofthe stator 3, and a pump-side member 2 a. A bearing support 7 and aturbine-side member 4 a are placed on the opposite side, and dynamicpressure grooves are formed in sliding faces of the flange portion 3 bof the stator 3 and the bearing support 7 (Japanese Patent Publication(Kokai) No. HE18-247251).

As shown in FIGS. 7(A) and 7(B), for example, herringbone-like or V-likedynamic pressure grooves 10, 10, . . . are formed in the surface of theside face of the flange portion 3 b of the stator 3, or, as shown inFIGS. 8(A) and 8(B), herringbone-like or V-like dynamic pressure grooves9, 9, . . . are formed in the surface of the side face of the bearingsupport 7. A dynamic pressure is generated by relative rotation of thestator 3 and the like, so that the thrust load is supported and thrustbearings or thrust washers are not required.

The stator 3 and the bearing support 7, in which the herringbone-like orV-like dynamic pressure grooves 10 or 9 are formed in the sliding face,are produced from a synthetic resin. The ATF (Automatic TransmissionFluid) which generates a dynamic pressure is sucked into the dynamicpressure grooves 10 (9) from the inner and outer radial sides of theside faces of the stator 3 and the bearing support 7 to join together inthe apexes of the dynamic pressure grooves 10 (9), i.e., in the centerof the sliding faces, with the result that the pressure is raised toexert the dynamic pressure effect. In such pressure rise, however, thepressure is generated at the junctions of the dynamic pressure grooves10 (9), but the high-pressure fluid has no way of escape, and hence thefluid temperature is abruptly raised in accordance with the slidingoperation of the side faces of the stator 3 and the bearing support 7.As a result, there arises a problem in that the sliding faces are easilyworn.

SUMMARY OF THE INVENTION

The invention has been conducted in view of the above-discussed problem.It is an object of the invention to provide an assembly of a one-wayclutch and a bearing in which a thrust load due to a stator can beabsorbed, a dynamic pressure can be generated, and, even when thepressure becomes high, the temperature is prevented from being abruptlyraised, so that wear and the like of sliding faces can be prevented fromoccurring.

In order to solve the problem, the present invention provides anassembly of a one-way clutch and a bearing in which a bearing is placedbetween a one-way clutch attached to a stator of a torque converter, anda pump member adjacent to a flange portion formed on the stator, and aturbine member adjacent to a bearing support which is placed on a sideopposite to the flange portion of the stator, and

dynamic pressure grooves (3 c) and an escape groove(s) (3 d) serving asthe bearings are formed in at least one of opposing faces of the flangeportion formed on the stator and the pump member, or opposing faces ofthe bearing support which is placed on the side opposite to the flangeportion of the stator, and the turbine member.

Furthermore, the present invention provides that the escape groove(s) isa ring-like groove (3 e) which is formed in a circumferential directionof a face, the dynamic pressure grooves being formed in the face.

Moreover, the present invention also provides that the escape groovesare grooves (3 f) which are radially formed at predetermined angularintervals in a circumferential direction of a face, the dynamic pressuregrooves being formed in the face whereat the dynamic pressure groovesare not formed.

Furthermore, the present invention additionally provides that a bearingsupport is placed in place of the flange portion of the stator.

Moreover, the present invention provides that the bearing support isused as the flange portion of the stator, and the flange portion of thestator is used as the bearing support.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1(A) is an axial section view of a stator constituting an assemblyof a one-way clutch and a bearing of the present invention, and FIG.1(B) is a side view of a flange portion.

FIG. 2 is a side view of a flange portion of a stator constituting anassembly of a one-way clutch and a bearing of the present invention, andshowing an embodiment in which dynamic pressure grooves and escapegrooves are densely formed.

FIG. 3 is a view showing an example which is a second embodiment of theassembly of a one-way clutch and a bearing of the present inventionwherein dynamic pressure grooves formed in a side face of a flangeportion of a stator, and a ring-like escape groove that elongates in acircumferential direction in junction points of the dynamic pressuregrooves is formed.

FIG. 4 is a view showing an example which is a third embodiment of theassembly of a one-way clutch and a bearing of the present inventionwherein dynamic pressure grooves are formed in a side face of a flangeportion of a stator, and grooves which interrupt the dynamic pressuregrooves are radially formed as escape grooves at predetermined angularintervals in a circumferential direction.

FIG. 5(A) is a section view of a bearing support constituting theassembly of a one-way clutch and a bearing of the present invention, andFIG. 5(B) is a side view of the bearing support.

FIG. 6 is an axial section view of an assembly of a one-way clutch and abearing of the conventional art showing an axial section of an assemblyof a one-way clutch and a bearing in which a thrust bearing and a thrustwasher are not used.

FIG. 7(A) is a partial axial section view of a stator constituting anassembly of a one-way clutch and a bearing of the conventional art, andFIG. 7(B) is a side view of the stator.

FIG. 8(A) is a partial axial section view of a bearing support which isplaced in a stator constituting an assembly of a one-way clutch and abearing of the conventional art, and FIG. 8(B) is a side view of thebearing support.

FIG. 9 is an axial section view of an assembly of a one-way clutch and abearing of the conventional art in which a thrust bearing and a thrustwasher are placed on both the sides of a stator wherein the one-wayclutch is disposed.

DETAILED DESCRIPTION

Hereinafter, specific embodiments of the invention will be describedwith reference to the drawings. In the following, description will bemade referring to FIG. 6 in order to avoid duplicated description, andthe same components will be described by using the identical referencenumerals.

FIG. 1(A) is an axial section view of a stator 3 constituting theassembly of a one-way clutch and a bearing of the invention, and FIG.1(B) is a side view of a flange portion of FIG. 1(A). The stator 3 isconfigured in the same manner as the stator shown in FIG. 6, and formedby a boss portion 3 a, and a flange portion 3 b formed by elongatingradially inward one side of the boss portion 3 a.

An outer race 6 a (see FIG. 6) of the one-way clutch is fitted into theinner side of the boss portion 3 a. The pump-side member 2 a (see FIG.6) is placed on the side adjacent and opposed to the flange portion 3 bof the stator 3 to form a small gap 21 therebetween. A one-way clutch isplaced and the bearing support 7 is placed on the side of the bossportion 3 a opposite to the flange portion 3 b. The turbine-side member4 a (see FIG. 6) is placed on the side adjacent and opposed to thebearing support 7 and forms a small gap 20 therebetween.

As shown in FIG. 1(B), herringbone-like or V-like dynamic pressuregrooves 3 c, 3 c, . . . are formed in the side face of the flangeportion 3 b of the stator 3 at predetermined intervals in acircumferential direction. The dynamic pressure grooves 3 c, 3 c, . . .are formed so that the resistance of the automatic transmission fluidwith respect to the relative rotation direction of the stator 3,indicated by the arrow P, is increased. Namely, the dynamic pressuregrooves 3 c, 3 c, . . . are formed so that, during relative rotation ofthe stator 3, the automatic transmission fluid is introduced from theinner and outer radial sides and joins in a rear center portion in therotation direction of the stator 3. The dynamic pressure grooves 3 c arenot limited to a herringbone-like shape or a V-like shape, and may haveany other shape such as a triangular shape as long as a dynamic pressurecan be generated. During relative rotation of the stator 3, a highpressure is generated in the gap 21 between the stator and the pumpsidemember 2 a, and hence such dynamic pressure grooves 3 c, 3 c, . . . havea function of a bearing. Therefore, a thrust bearing or a thrust washerwhich is necessary in the conventional art is not required.

In the side face of the flange portion 3 b of the stator 3, the dynamicpressure grooves 3 c, 3 c, . . . are formed, and also escape grooves 3d, 3 d, . . . for allowing the automatic transmission fluid to escapeare formed. In order to allow the automatic transmission fluid tosmoothly escape by using a centrifugal force generated during relativerotation of the stator 3, each of the escape grooves 3 d is formed intoa curved shape such as that constituting a part of a volution (spiral)so that the inner radial side is in the forward side and the outerradial side is in the rearward side. When the escape grooves 3 d, 3 d, .. . are formed together with the dynamic pressure grooves 3 c, 3 c, . .. in the side face of the flange portion 3 b of the stator 3 in thisway, the dynamic pressure generated in the center of the side face ofthe flange portion 3 b can be allowed to escape at a certain degree.Therefore, abrupt generation of a high pressure and temperature rise ofthe automatic transmission fluid which are caused by the rotation can besuppressed.

FIG. 2 is a side view of the flange portion 3 b of the stator 3 in whichwide dynamic pressure grooves 3 c, 3 c, are densely formed in the sideface. Also in the surface of the flange portion 3 b in which the dynamicpressure grooves 3 c are formed, volute (spiral) escape grooves 3 d areformed so that the inner radial side is in the forward side with respectto the relative rotation of the stator 3 and the outer radial side is inthe rearward side, and that the automatic transmission fluid is allowedto escape by using a centrifugal force.

Next, FIG. 3 is a side view of the stator 3 of a second embodimentconstituting the assembly of a one-way clutch and a bearing of thepresent invention. In the stator 3, a ring-like circular escape groove 3e having a predetermined width is formed in a circumferential directionin junction points of the dynamic pressure grooves 3 c, 3 c, . . . whichare formed in the side face. Namely, the conventional dynamic pressuregrooves 10, 10, . . . such as shown in FIG. 6 cannot allow a dynamicpressure generated in the center of each groove to escape. By contrast,in the embodiment, between the center circular escape groove 3 e and theouter portion of each of the dynamic pressure grooves 3 c that arepositioned more outward than the escape groove, paths are formed so asto connect the grooves. Therefore, the circular groove 3 e functions asan escape groove, so that the high pressure of the automatictransmission fluid which is generated in the center portions of thedynamic pressure grooves 3 c, 3 c, . . . can be allowed to escape to theoutside of the stator 3 by a centrifugal force due to the relativerotation.

FIG. 4 is a side view of the stator 3 of a third embodiment of thepresent invention.

In the embodiment, the dynamic pressure grooves 3 c, 3 c, . . . areformed in the side face of the flange portion 3 b of the stator 3, andradial grooves 3 f, 3 f, . . . are radially formed at predeterminedangular intervals in a circumferential direction. The radial groovesserve as escape grooves which interrupt the dynamic pressure grooves 3c, 3 c, . . . in four places (at an interval of 90 deg.) in thecircumferential direction where at the dynamic pressure grooves are notformed. The dynamic pressure of the automatic transmission fluid whichis generated by the relative rotation of the stator 3 can be allowed toescape to the outside of the stator 3 through the radial grooves 3 f, 3f, . . . . The radial grooves 3 f, 3 f, . . . which interrupt thedynamic pressure grooves 3 c may be formed with reducing their width,and radially increased or reduced.

In the assembly of a one-way clutch and a bearing of the invention, thestator 3 has been exemplarily described. As shown in FIGS. 5(A) and5(B), alternatively, also in a side face of the bearing support 7,dynamic pressure grooves 7 a may be similarly formed and escape grooves7 b may be formed, or a circular groove or radial grooves which aresimilar to the ring groove 3 e or the radial grooves 3 f may be formed.

In addition to the above-described embodiments, dynamic pressure groovesand escape grooves may be formed also in the surface of the pump-sidemember 2 a which is placed to form the small gap 21 with respect to theflange portion 3 b of the stator 3, and in that of the turbine-sidemember 4 a which is placed to form the small gap 21 with respect to thebearing support 7. In the stator 3, the flange portion 3 b may not beformed, and a bearing support may be placed. Conversely, a flangeportion may be placed on the side of the bearing support 7 of FIG. 1,the flange portion 3 b may be placed on the side of the pump-side member2 a of the stator 3, and dynamic pressure grooves and—escape grooves maybe formed in the surfaces of the portions.

In the above-described embodiments, the dynamic pressure grooves 3 c (7a), the escape grooves 3 d (7 b), and the like are formed in the sideface of the flange portion 3 b of the stator 3, and the bearing support7. Alternatively, the dynamic pressure grooves 3 c and the escapegrooves 3 d (3 e, 3 f) may be formed in the flange portion 3 b of thestator for 3, and a thrust bearing or a washer may be placed between thebearing support 7 and the turbine-side member 4 a. Alternatively, thedynamic pressure grooves 7 a and the escape grooves 7 b may be formed inthe side face of the bearing support 7, and a thrust washer or a needlebearing may be placed on the side of the flange portion 3 b of thestator 3.

As described above in detail, according to the assembly of a one-wayclutch and a bearing of the present invention, the automatictransmission fluid of elevated temperature can be discharged whilemaintaining an adequate dynamic pressure between the stator and a pumpmember, and the stator and a turbine member. Furthermore, cold automatictransmission fluid is sucked from the dynamic grooves to the slidingfaces of the stator and the bearing support to exert the dynamicpressure effect, and the automatic transmission fluid of elevatedtemperature is discharged from the escape grooves. Therefore, also wearof the sliding faces can be reduced.

What is claimed is:
 1. An assembly of a one-way clutch attached to astator of a torque converter, a pump member, a turbine member, and abearing support, comprising: said stator having a stator flange portiondisposed adjacent said pump member and defining a first gaptherebetween; said bearing support being disposed on a side of theone-way clutch opposite that of said stator flange portion and beingdisposed adjacent said turbine member to define a second gaptherebetween; and dynamic pressure grooves and escape grooves, servingto function as hydraulic bearings, being formed in at least one of: atleast one annular face, having an inner circumference and an outercircumference, of opposing faces of said stator flange portion and saidpump member; and at least one annular face, having an innercircumference and an outer circumference, of opposing faces of saidbearing support and said turbine member; wherein said escape groovesinclude grooves radially-formed at predetermined angular intervals in acircumferential direction of said at least one annular face andextending from the outer circumference to the inner circumference ofsaid at least one annular face, and said dynamic pressure grooves areformed in said at least one annular face except where said escapegrooves are formed and each said dynamic pressure groove has two openends, at least one of said open ends communicating with said escapegroove and other said open ends communicating with exterior of the innercircumference or exterior of the outer circumference of said at leastone annular face.
 2. The assembly according to claim 1, wherein saidstator flange portion is formed as a bearing support.
 3. The assemblyaccording claim 1, wherein said bearing support is said stator flangeportion of said stator, and said stator flange portion of said stator issaid bearing support.